This project is designated to determine how 2 designated control gene loci (I and B1) of the fowl effect their changes during melanogenesis with regard to the structural c and pk loci. During the year 1/1/78-12/31/78 we propose to 1. extend heterokaryon complementation analyses to include combinations of the I locus with c, ey, B1 and pk, 2. analyze for pigment production, fusion products beyween wild type fibroblasts or fibroblast minicells and mutant amelanotic melanocytes or their cytoplasts.